•Bariatric surgery, (from the Greek 'baros' meaning weight) indicates a variety of gastrointestinal surgical procedures primarily aimed at inducing durable weight-reduction in morbidly obese patients by reducing the stomach size or bypassing a part of the small intestine, or by a combination of both , and as a consequence reducing intake and/or absorption of nutrients.

•Over several decades of clinical use and research studies, it has become clear that the reduction of food intake after bariatric surgery is not just the result of mechanical reduction of the stomach size , modulation of hormones and neural signals that regulate the feelings of hunger and satiety also plays an important role.

Benefits of bariatric surgeryAlthough originally developed merely for weight reduction, bariatric surgery results in benefits beyond just weight loss. In fact, bariatric surgery can prevent or dramatically improve the obesity related comorbidities including diabetes, high blood pressure, high cholesterol and triglycerides, sleep apnea, cardiovascular disease and others.

Type of proceduresPurely RestrictiveAdjustable gastric bandingIn this procedure an inflatable silicone band is placed around the upper part of the stomach. The new, small upper stomach pouch limits the amount of food that can be consumed at one time, and an narrowed stomach outlet increases the time it takes for the stomach to empty. Sleeve gastrectomy75-85% of the stomach is removed, creating a smaller reservoir that limits the amount of food that can be consumed.Gastric PlicationIn this procedure part of stomach is folded inside the lumen , so that stomach capacity decreases, and the amount of food intake reduces .Adjustable gastric banded plicationThis procedure depends on plicating the stomach wall as in gastric plIcation , then placing a silicon band around the upper part of the plicated stomach .

Restrictive > Malabsorptive Roux-en-Y gastric bypassA small pouch is created at the top of the stomach. Part of the intestine is then connected to the top of this pouch so the limiting the amount of food intake and decreasing fat and carbohydrate absorption.

Malabsorptive > RestrictiveBiliopancreatic diversion (BPD) with or without duodenal switch : Part of the stomach is resected, creating a smaller stomach (however the patient can eat a free diet as there is no restrictive component). The distal part of the small intestine is then connected to the pouch, bypassing the duodenum and jejunum.

Compared with a healthy weight man, an obese man is:• five times more likely to develop type 2 diabetes• three times more likely to develop cancer of the colon• more than two and a half times more likely to develop high blood pressure – a major risk factor for stroke and heart disease

An obese woman, compared with a healthy weight woman, is:• almost 13 times more likely to develop type 2 diabetes• more than four times more likely to develop high blood pressure• more than three times more likely to have a heart attack

Psychologically, being overweight can affect the body image and damage self-esteem. In some cases this can cause social anxiety and depression.

The following medical conditions are also more common in obese people than in those of normal weight:• osteoarthritis• high cholesterol • Cardiovascular diseases• Obstructive sleep apnea• Fatty liver.

How is obesity treated?Dietary changesfollowing low-caloric diet and shifting to healthier food that contains less fat and carbohydrates .Exercise and activitywith aim for at least 150 minutes of moderately intense exercise each week (ideally 30 minutes at least 5 days a week).Medicationsweight-loss medication is meant to be used along with diet, and exercise , not instead of them. Medications may be indicated if:．Other methods of weight loss haven't worked．Body mass index (BMI) is 30 or greater．Body mass index (BMI) is greater than 27 with medical complications of obesity, such as diabetes, high blood pressure.Weight-loss surgeryeven though recommended , most therapies have not been successful in keeping sustained weight loss , and controlling obesity related diseases . until now, only bariatric surgery has proven to result in effective and durable weight loss , and resolution or improvement in obesity related diseases .